Influenza the Story of Pandora\'s

Influenza

The story of Pandora's Box is the best one to use to explain the occurrence of disease in the world. This may be the simplest way to accept in ourselves that there are things in this world that is beyond our control, no matter how progressive we can be. Diseases that have been plaguing mankind since time immemorial made great changes in history, always the turning point that produced dramatic changes in the whole world. Humans came to acknowledge their weaknesses, but at the same time, determined to battle their fears one at a time. Bubonic plague, the most famous disease that has been recorded, not only caused a great loss in the population, but has been so sensationalized due to its effect in the economy. Perhaps, flu should be given a space in the history for mention of diseases that has a devastating magnitude, if not equal to that of the plague.

Influenza spread around the world in pandemics which occur in season. The most famous of which is the "Spanish flu" in 1918 which killed almost 50 million people worldwide. Two other pandemics hit the world, the "Asian" pandemic in 1957 and "HongKong" pandemic in 1968. The pandemics of influenza occur when it acquires a new hemagglutinin or neuraminidase that usually come birds, and sometimes swine. Influenza caused seasonal epidemics that had a widespread effect on economics, education and quality of life. (2008, Influenza)

Influenza or "flu," as it is known in the vernacular, is an illness characterized by chills, colds, coryza, mylagia, headache, and coughing. It is a very contagious disease and caused by the family Orthomyxoviridae RNA virus, and often affects those of the extremes of ages - the young and the elderly through respiratory droplets or aerosols or through contact with saliva, feces, blood, and nasal secretions. It can also be transmitted through contact with bird droppings. Infection happens when the body is unable to remove these viruses through cough reflex and escape neutralization by our immune system. Replication and multiplication then ensues producing new virus promoting spread of virus that overcome the respiratory epithelium. Respiratory superficial mucosa is desquamated, but the basal layer is spared. Respiratory cellular damage takes up about one month but this window time gives opportunity to superimposed bacterial infection. The local symptoms produced during the course of the illness are due to edema and mononuclear infiltrations in response to the destruction of respiratory cells. (Brook et. al. 1995)

Incubation varies from 1 to 4 days and viral shedding starts the day preceding onset of symptoms, then peaks within 24 hours, persists for two days then declines. Influenza virus can be isolated and identified. Nasal washings and throat swab specimens are the best specimens to be used. For viral culture, embryonated eggs and primary monkey kidney cells are the best choice. However, continuous cell lines derived from canine monkey or rhesus monkey kidney are becoming popular. Viral isolates, the influenza type and subtype, can be identified through the process of hemagglutinin inhibition. (2008 Influenza viruses)

Flu can be devastating to the elderly, debilitated and the young since it may progress to pneumonia. Even to normal healthy individual who are afflicted, it can cause great general discomfort.

The Culprit: Influenza virus, Family Orthomyxoviridae

Myxo" denotes the affinity for mucin and the ability to attach to glycoprotein cell surface receptors. Two families belong to this one, the Paramyxovirus and the Orthomyxovirus. Influenza virus belong to the latter.

It was only perhaps during in the 1930's when the etiologic agent was identified to be a virus, rather than a bacteria.. Influenza virus has five genera: InfluenzavirusA, InfluenzavirusB, InfluenzavirusC, Isavirus and Thogotovirus. The virus that causes influenza has three immunologic types: A, B and C. Influenza type a is known to have great antigenic changes, type B to a lesser degree. Type C appears to be the most stable antigenically among the three. Types a and C. affect multiply species, while Type B exclusively infects humans. (2008 the Flu)

Influenza virus a is the prototype of the Influenza virus, and the structures of other Influenza virus are almost the same.

Influenza virus are usually spherical, but can also be globular and about 100 nm in diameter, sheathed in a lipid bilayer that is studded with two integral proteins, the some 500 molecules of hemagglutinin (H) and some 100 molecules of neuraminidase (N) and within it some 3000 molecules of matrix protein and 8 pieces of RNA which is associated with many copies of a nucleoprotein, several molecules of the three subunits of its RNA polymerase and some "non-structural" protein molecules of uncertain function.

The eight RNA molecules include the HA genes which encodes for the hemagglutenin, NA genes for the neuraminidase, NP for nucleoprotein, M genes for two proteins, a matrix protein and an ion channel spanning the lipid bilayer, the NS genes that encodes 2 different non-structural proteins and one RNA molecule for each of the three subunits of the RNA polymerase. (2008 the Flu)